Liquid oxygen explosive



- Patented Ma 31, 1938 j s ArEs PATENT OFFlCE Q. Q fLIQUID ox l lmo m Y. v

No Drawing.- Application August 19, 1937.

Serial No. 159,914

6 Claims.

.In' the' -use of liquid oxygen explosives a suitable amount of carbon or carbonaceous material a v f is placedin a bag or wrapper or made into a cartridge',-,and liquid oxygen is added thereto. The

cartridges actually used in this manner may be i of considerable size and when they are to be used, theya'rei placed or dropped in a hole or bore to t 10 be blasted," tamped in place and then detonated. The most;fserious objection to the use of liquid oxygen explosives has been that they are sensitivefto'sparks'or flame. As a. result, premature explosions' have been caused by stones or other 1.; objects falling on" the saturated cartridges as they are being lowered into drill holes or such f explosions have been caused by shocksor sparks accidentally transmitted to the cartridges in transit. ,Many .attempts have been made to overcome -lthis fault. In the prior patent of GeorgeSt-JohnPerrott and me, No. 1,860,816, granted May 31, 1932 wehave disclosed and claimed a method of regulating the sensitivity of. explosives of this type whereinan incombustible :amaterial' in'a'finer state of division than the carbon is added to the carbon. Likewise in the Holderer and Clark Patent No. 1,865,104, granted June 28, 1932 we have-disclosed and claimed the use-of a binder in an amount sufficient to agglomerate thecarbonaceous material without appreciably" affecting its porosity, and in my prior Patent No.* 1,960,907, granted May 29, 1934, I have disclosed and claimed the use of carbonized lignin residues having a moisture content greater than 8 percent.

While each of these methods has resulted in the production-of liquid oxygen explosives which are sai'er' to handle than would otherwise be the case, I have now found that the sensitivity of 40 such cartridges. to outside spark or flame infiuence canbe greatly minimized by treating the carbonaceous mater l with a fire-proofing sub stance preierably in I or wrappersin whic 'the carbonaceous material 1S contained may be impregnated with fireproofing.material. Any of the ordinary fire proofing'salts. may be employed for this purpose. Oi. s'uchusalts I prt' to use either dibasic or monobasic' ammon .1 phosphate; My inven- 5 0 'tion; however-{is .n... limitedto theuse of this particular lsalt and cium ,chloride, magnesium sulphate, sodium silicate eborax,sodiumbromide, sodium tungstate,

magnesium phosphate, phosphoric acid, monolution. Likewisethe bags equivalents therefor cal- 'zinc chloride, tr'i-ba'sidzinc phosphate, tri-basic basic magnesium phosphate, boric acid, monobasic zinc phosphataaluminum sulphate, am--' monium bromide, ammonium chloride and ammonium sulphate. Combinations of these or similar chemicals may be desirable both from the 5 standpoint of efiectiveness and cost and the invention includes the use of two or more of these .materials together. Also wide latitude of the strength of solutions employed is within the scope of the invention and the strength employed is 10 based largely on the cost of the chemicals as all In practicing the invention the carbonaceous material is first treated with. the fire-proofing material and then placed in the bags or casings in the usual way. I preferably employ a water soluble, fire-proofing material and as a specific 30 I example a solution of ammonium phosphate of desired strength may be first formed. The solution is then added to the carbonaceous material up to 20% by weight. The water and the fireproofingmaterial are allowed to remain in the 35 carbonaceous material and the carbonaceous material then placed in bags and liquid oxygen added thereto in the .usual manner.

Instead of using a water-soluble, fire-proofing material, a material that is not water-soluble may 40 be empioyedand thoroughly mixed with the carbonaceous material before the liquid oxygen is added thereto.

The addition of the fire-proofing material in the amounts stated reduces the sensitivity of the 4 completed cartridge to a point where it is'safer to handle but not enough to destroy its usefulmess. The cartridge so produced is thus capable of being detonated in the usual manner when desired but is less liable to premature explosions caused by stones 'or other objects falling on the cartridge as it is being lowered into drill holes and is also less liable to explosion by casual flames, such as cigarettes, sparks, etc.

The carbonaceous material, treated as above 66 described, may be employed in the usual wrappers or bags of cotton fabric or the bag or wrapper may. also be treated with the fire-proofing agent. When the bag is to be treated, the solution is prepared as above described and containing about one gallon of water to one pound of the salt. Thebags or the material from which the bagsare to be made, are soaked in this solution and allowed to dry. a

As an alternative procedure, the bag may be filled with a carbonaceo s material in the usual way and then treated 1 th the fire-proofing solution, either by spraying the finished bag or by coating it by placing it in a vessel or trough containing the solution. In this way the bag will become saturated with the fire-proofing solution and an outer layer of the carbonaceous material near the bag will also become saturated; If such outer layer of the carbonaceous material is saturated, it is not necessary to saturate the'carbonaceous material throughout as this treatment is eflective in stopping both flaming and glowing of the carbonaceous material;

While the present invention may be practiced with any type of carbonaceous material capable of absorbing liquid 'oxygen I prefer to employ granular carbons having a high degree of absorption for liquid oxygen, or other explosives. A granular carbon of the type commercially known'as'Bugbird carbon, made in accordance with the Bugbird Patents Nos.'1,'706,871, 1,779,530 and 1,781,214, may be used. This material is obtained by carbonizing liquors rich in dissolved lignins, such as those derived from the manufacture of wood pulp by the alkali (soda) process.

The carbonized lignin residues are leached to remove water soluble impurities and then sub-- mitted to a-slight grinding action to reduce the grains to a more or less-uniform size. This prograins are not more than about one-quarter inch in their longest dimension and sothat not more than about 25 percent of the material will pass through a 100 mesh screen.

I am aware or prior patents disclosing -th etreatment of bags or casings of explosive cartridges with fire-proofing materials for the pur pose of making. them flre-damp-prooi. v damp-proofing is not to be confused with the treatment of the carbonaceous material itself forv the sensi-tivity'ot the' cartridge. This phrase means reducihg the flame the purpose of decreasing Firetemperature of theexplosive mixture to reduce of my invention the cartridge m" terial itself is treated to lower -its sensitivity casual flame without affecting its ability toy absorb liquid oxygen and without destroying its propulsive strength. I

I claim:

bonaceous material in granular form impregthe cartridge casing to. on it arid confine the.

nated with a solution of a fire-proofing material.

2. A liquid oxygen explosive comprising carbonaceous material ingranular form'impreg mated with a solution of ammonium phosphate.

3. A liquid oxygen explosive comprising carbonaceous material in I granular form impreg nated with a solution of calcium chloride.

4. The" herein described i'riethodfwhich com-" prises impregnating granular carbonaceous material with a solution of ii -proofing material,

ing liquid oxygen thereto;

5; The herein described-method which complacing the material in a bag or casing and addprises impregnating granular carbonaceous material with a solution of ammonium phosphate, placing thematerial infa bag or casingand vadd- I ing liquid oxygen thereto. duces a granular carbon in which the largest 6. The herein described method which comprises impregnating granular carbonaceous material with a solution of calcium chloride, placing the material in a bag or casingflandadding liquid oxygen theretm, f v

' GEORGE BURKLE HOLDERER.

v I 20 v 1. A liquid oxygen explosive frcomprising car-'- I 

